Do you use pattern blocks?
I have a huge tub full of them and decided I wanted some mats for the kids to make some designs. They do a great job free-forming it, but I think it's important for them to also follow puzzle images where they need to figure out the correct shape.
I went to my local teacher store for a book but couldn't find one.
After a quick google search I came across this amazing site called Pre-Kinders!!
This generous person has a TON of free mats you can use. Be sure to follow her terms and have fun!